1. Field of the Invention
The present invention relates to a synthetic resin leather which is suitable for use in general applications such as interior finishing materials and/or seats for automobiles, cover materials for furniture, etc.
2. Description of the Related Art
It is conventionally well known that synthetic resin leathers containing substrates and synthetic resin layers composed of flexible polyvinyl chloride and attached to one side of the substrates are conventionally used as materials for seat covers of automobiles or chairs. The substrates usually comprise both-sided knitted fabrics prepared by knitting single spun or mixed spun fibers made of rayon, cotton, polyester, nylon, acryl, or urethane.
However, the both-sided knitted fabric has an elongation in a longitudinal direction less than that in a transverse direction, tensile strength in the longitudinal direction higher than that in the transverse direction. Therefore, in the case where a synthetic resin leather made of such knitted fabric is applied to raw materials for car seat covers or chair covers, problems such as the generation of distortion and/or warp in curved portions, or crimp, collapse in shapes, breaking, etc. are caused in the leather due to frequent load of having users sitting in the car seats or chairs.
Also, although the substrate exhibits natural softness or flexibility (feeling) and has a function of increasing the manufacturing yield or improving needlework as a sheet assembly is formed using the needlework for the production of seats or chairs, it is difficult to exhibit the natural softness or the flexibility if the synthetic resin leather using the conventional knitted fabric having small thickness and higher tensile strength in the longitudinal direction is employed as the cover material of the car seats or other chairs, thereby resulting in concerns of having unsatisfactory feeling. Further, the known leather has problems that it is like to generate crimp during the formation of the sheet assembly and needs additional processes to flatten out crimp by exposing the leather to steam after sewing.
On the other hand, there had been proposed many studies for formation of loops in the single side knitted fabric made by grey sheeting and number of loops made of the both-sided knitted fabric and the like among the synthetic resin leather having reduced difference of elongations between in the longitudinal direction and in the transverse direction.
But, the former synthetic resin leather has a thinner thickness of the substrate because it is formed of the single side knitted fabric, inducing a defect of insufficient feeling for the leather.
Since the later synthetic resin leather made of the both-sided knitted fabric is fabricated by fibers having little elongation such as cotton, rayon, polyester, nylon, vinyl chloride fiber, etc., the leather has low elongation in the transverse direction and increased tensile strength in the transverse direction. Consequently, the above leather does not express the natural softness and/or the flexible feeling, thereby having a disadvantage of lack of leather-like feeling.